The present invention generally relates to transmissions for power machines. In particular, the present invention relates to a transmission on a power machine with a spherical bearing.
Power machines, such as loaders, typically have a number of power actuators. Such actuators can include, for example, drive actuators or motors which provide traction power to the wheels or tracks of the machine. The actuators can also include those associated with manipulating a primary working tool, such as a bucket. In that case, the actuators include lift and tilt actuators. Of course, a wide variety of other actuators can also be used on such power machines. Examples of such actuators include auxiliary actuators, hand-held or remote tool actuators or other actuators associated with the operation of the power machine itself, or a tool coupled to the power machine.
The various actuators on such power machines have conventionally been controlled by mechanical linkages. For example, when the actuators are hydraulic actuators controlled by hydraulic fluid under pressure, they have been controlled by user input devices such as handles, levers, or foot pedals. The user input devices have been connected to a valve spool (of a valve which controls the flow of hydraulic fluid under pressure to the hydraulic actuator) by a mechanical linkage. The mechanical linkage transfers the user input motion into linear displacement of the valve spool to thereby control flow of hydraulic fluid to the actuator.
Electronic control inputs have also been developed. The electronic inputs include an electronic sensor which senses the position of user actuable input devices (such as hand grips and foot pedals). In the past, such sensors have been resistive-type sensors, such as rotary or linear potentiometers.
In the past, transmissions have included chain drive transmissions. A hydraulic motor has been coupled to an axle through a sprocket, via a chain linkage. Rotation of the hydraulic motor drives rotation of the axle and consequent rotation of the wheels. However, past transmissions have been configured such that the inboard end of the axle is supported inside a differential by a tapered roller bearing arrangement. Other transmissions have included two sets of bearings. An inboard and an outboard set of bearings are configured relative to the axle to handle both axial and radial loads on the axle.
A transmission in a power machine includes an axle having an inboard and outboard end. The outboard end is coupled to a wheel through a universal joint. The inboard end is coupled, through a sprocket assembly and chain drive linkage, to a hydraulic motor. The axle is supported at its inboard end by a single spherical bearing.